Cellular telephone manufactures strive to continually provide new and innovative services in an attempt to keep existing customers and draw in new customers in an industry that is already very competitive. Location based services enable personalized services to be offered based on a person's (or item of the person) location. Services include, for example, security reporting, fleet and resource management, location based information, vehicle tracking, person-to-person location, and messaging applications.
Location-based information services allow subscribers to access information for which the information is filtered and tailored based on the location of the requesting user. Service requests may be initiated on demand by subscribers, or automatically, when triggering conditions are met, and may be a singular request or result in multiple deferred responses. Examples of location based information services include the following: navigation to guide the user to his or her destination; city sightseeing to describe historical sights, find restaurants, the airport, bus terminal, etc.; location dependent content broadcast, that support broadcasting content to a user in a certain geographical area; and mobile yellow pages for finding telephone numbers and addresses.
Public communication systems are highly standardized so that device manufacturers, such as cell phone manufacturers, can take advantage of economies of scale by manufacturing different devices using the same communication interfaces for all their customers. Thus, mobile communication devices that work with a first network can also be used with a second network that adheres to the same standardized architecture and signaling protocols as the first network. Standardization has the further advantage that communication networks can easily pass information, such as cellular phone calls or data messages, between themselves if the interface between the networks is standardized.
The basic components of a standards-based location services (denoted LCS—LoCation Services) architecture include an LCS client and an LCS server. The LCS server is a software and/or hardware component that consists of a number of location service components and bearers needed to service the LCS clients. An example of a location service bearer might be a software application for fleet resource management. The LCS server may receive location information requests, process the requests, and send back responses to the received requests. The LCS server supports location based services in parallel with other telecommunication services such as speech, data, messaging, other teleservices, user applications and supplementary services and therefore enable the market for services to be determined by users and service providers.
An LCS client is a software and/or hardware component that interacts with the LCS server for obtaining location information for one or more Mobile Stations within a specified set of parameters. LCS clients subscribe to LCS in order to obtain location information. LCS clients may or may not interact with human users, and may be responsible for formatting and presenting data and managing the user interface (dialogue).
The LCS client and server use LCS messages to exchange information, and each LCS message contains a set of parameters. The LCS messages may comprise a location service request and/or a location service response. The location service request can be of two types: an immediate request that receives an immediate response; and a deferred type, whose response time is delayed (or event-driven) and a response to which can include one or more service responses. A location service request report provides the result of a deferred location service request from the LCS server to the LCS client. The report is provided using a dialog between the client and the server that is initiated by the server.
One disadvantage of current LBS (locations based service) systems is that they are constructed so that the network based LCS must send a message to the mobile station, requesting that the mobile report its position. Thus, at least two messages are required every time a mobile reports its location to the network, one message from the network to the mobile and a response from the mobile to the network. In communication networks that may provide services to many millions of customers, such as cellular networks, it is desirable to reduce communications signaling to the greatest extent possible. Excess signaling can choke the network and cause reduced service quality for all customers.
One implementation provides a similar proprietary mobile-based GPS (Global Positioning System) solution based on a proprietary protocol (MPTP-Mobile Positioning Telematics Protocol). Recent products also provide assistance data capability, but in an indirect manner, as they are relatively independent of the underlying wireless network. Such an implementation, however, besides being proprietary, also has implications on location accuracy and reporting latency performance.
Current LCS implementations do not provide the capability to place a mobile terminal in tracking mode for autonomous periodic or event-driven location reporting to the network. Tracking involves “deferred” location reporting at the occurrence of event triggers that are defined in the location tracking request message. For example, a location-tracking request may be to provide location reports every ten minutes for a period of two hours; the event trigger in this case is realized by a timer that triggers every ten minutes for the duration of two hours. One realization of a location server is the GMLC (Gateway Mobile Location Center) as defined in GSM (Global System for Mobile Communications) and UMTS (Universal Mobile Telecommunication System) (using the control plane of the wireless network). However, tracking (“multiple reports”) is currently not supported in the wireless radio network (for clients external to the radio network), and GMLC-based tracking supports limited triggers. The GMLC can be requested to provide periodic location reports to the client, but each report has to be individually generated by a GMLC request to the wireless network, such that the signaling overhead is costly and only tracking based on periodic reporting is possible.
What is needed is an improved location server implementation.